This invention relates to equipment employed for developing film. More particularly this invention relates to structures employed for holding sheet photographic film for developing.
Sheet film is widely used commercially, particularly the 4.times.5" (about 10.2 .times. 12.7 mm) size. The film is contained in a holder structure, exposed, and later removed from the holder structure for developing. The film is generally developed by dipping it into tanks containing developing chemicals. Such tanks are generally rectangular and have an open top. Racks holding the film are inserted through the open top such that the developing chemicals may reach the film. Such racks generally employ a plurality of clamping structures, each sheet of film being held by one, or clamped between two, such structures. The film must be developed in complete darkness, and current rack structures are not easily operable in such conditions.
Some racks have been developed which are employed to develop film in conditions of other than complete darkness. The structures necessary to shield the film from light while being developed result in the rack being more complex and expensive to manufacture.
Certain equipment has been developed which employs a tank rotatable about a horizontal axis. These tanks are commonly employed to develop 35mm, 120mm and roll film such as is used by the ubiquitous "instamatic" type cameras. The tank has a reciprocating rolling motion to insure even pick-up of developing fluid. Such automatic methods have not been employed for developing sheet film, a suitable rack for the film not yet having been devised.